During the past 25 years or so, bakeries have introduced as standard products hamburg and hot dog or frankfurter rolls which are sliced between the upper and lower portions thereof for a substantial part of the total area of the rolls but leaving a so-called hinge portion along one edge by which the upper and lower portions of the sliced rolls still are connected. In particular, this facilitates packaging the rolls and, in addition, also facilitates the handling of the rolls when introducing hamburgs and hot dogs or frankfurters respectively to the different types of rolls which are shaped respectively for such contents. More recently, however, a very substantial number of chains of restaurants and quick service establishments have popularized hamburgers of various kinds with numerous types of dressing, as well as multiple layers thereof and these products are advertised under various fanciful names by the respective chains of outlet dispensers. Particularly when multiple layers of hamburgers and the like are disposed between top and bottom portions of hamburg rolls and especially those which are circular in configuration, it is essential that the rolls be sliced entirely through the complete area of the rolls. However, to facilitate packaging and handling of such sliced rolls, the top and bottom portions must be maintained in contiguous relationship, especially while being sliced.
The tremendous volume of rolls of this type which are consumed by the public at present necessitates the slicing of such rolls by machine rather than by manual means and one condition which is insisted upon by the chains of restaurants and other food dispensing establishments which purchase said rolls from bakeries and dispense the same to the public is that the bottom portion or section of each roll must be of uniform thickness throughout, particularly to facilitate the formation of a complete product which comprises the placing of one or more hamburgers, slices of cheese, dressings of various kinds, lettuce and the like in the completed product, all of which is built up upon the foundation of the bottom section of the roll.
At present, it is common practice to slice rolls of the type referred to above by so called band type knife slicers in which an endless flexible knife blade is supported by a pair of similar rollers respectively mounted adjacent opposite sides of a traveling conveyor of predetermined width, said knife being supported by said rollers to dispose one section of the knife, usually the lower section, at a predetermined level above the upper surface of the conveyor which is utilized to feed successive rows of rolls to said knife to be sliced thereby. One problem encountered in successfully slicing the rolls with a band knife of this type is that the roll must be held in reasonably firm contact with the conveyor to insure that the roll passes to and beyond the section of the endless knife which slices it. Such pressure is accomplished at the present in various ways, such as by narrow, horizontal belts or equivalent means which tend to exert relatively uniform pressure across the entire upper surface of the rolls.
When substantially uniform pressure is applied to the upper surface of rolls being sliced, for example, by an endless band type blade, there is no means provided to compensate for rolls of uneven thickness. For example, when hamburg type rolls are baked, they sometimes are relatively thin along one side and much thicker along the opposite side. If some type of pressure means is utilized to engage substantially the overall upper surface of rolls to maintain the same in frictional contact with the feeding conveyor of the machine in order to insure movement of the rolls to and past the operative section of the endless band type knife blade, when a roll of uneven thickness, such as a so-called "lopsided" roll is engaged by such pressure means, it will compress the upper surface of the roll so as to be substantially parallel to the bottom surface thereof but, after the roll is sliced, the product which emerges beyond the knife section will comprise top and bottom sections which are both of uneven thickness and therefore are lopsided. This is unacceptable to establishments of the type referred to above which now dispense millions of hamburger-like products of many different types each day at present and these establishments insist upon the sliced lower portion of each roll being of uniform thickness throughout and not lopsided.